I am not familiar with many of the programs but overall I believe there are 22. My program (Midwestern Universtiy-St James) is pretty solid. The major plus is that you will see tons of the bread and butter type stuff at two community hospital settings with tons of angio as well. The major disadvantage is you will not see newer imaging modalities and research is very limited.
Cardio in the osteopathic world is also very competitive. I would not shy away from any program. Apply broadly and increase your chances. Our program is taking 2 and thus far I am the only potential applicant applying from within.
I know of Botsford and the UMDNJ program as well. both very solid. There is a new program at Palmetto in Florida. I rotated there as a student and I am not too optimistic for that place. hope some of this helps. take care